Function of ADAR1 in Hematopoietic and Leukemia Stem Cells

ADAR1 在造血干细胞和白血病干细胞中的功能

• 批准号: 8301064
• 负责人: Qingde Wang
• 金额: $ 19.67万
• 依托单位: UNIVERSITY OF PITTSBURGH AT PITTSBURGH
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-07-20 至 2014-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8301064
• 关键词: Accounting; Address; Adult; Animals; Biological Assay; Biological Process; Biology; Catalytic Domain; Cell Death; Cell Transplantation; Cells; Cessation of life; Code; Development; Dissection; Embryo; Enzymes; Excision; Future; Gene Deletion; Genes; Goals; Hand; Hematopoiesis; Hematopoietic; Hematopoietic stem cells; Homing; Immunology; Knock-in Mouse; Knock-out; Knowledge; Lead; Light; Modeling; Molecular Target; Monitor; Mus; Mutate; Pathway interactions; Phenotype; Play; Point Mutation; Population; Proteins; RNA Editing; Regulation; Reporting; Role; Science; Site; Spices; Stem cells; Therapeutic; Transcript; Translations; Transplant Recipients; Variant; Work; dsRNA adenosine deaminase; embryonic protein; experience; improved; in vivo; knockout gene; leukemia; leukemic stem cell; mouse model; prevent; progenitor; promoter; protein structure; self-renewal; skills; stem

DESCRIPTION (provided by applicant): This project is to define the function of RNA editing enzyme adenosine deaminase acting on RNA 1 (ADAR1) in hematopoietic and leukemia stem cells. Particularly the requirement of RNA editing activity of ADAR1 in these stem cells will be determined. ADAR1 is an essential protein for embryonic and adult hematopoiesis, while the leukemia cells are more susceptible to the gene deletion that codes ADAR1. Whereas hematopoietic repopulation in the recipients by transplanted hematopoietic stem cell (HSC) is suppressed in the absence of ADAR1, the homing and self-renewal capacities are intact. Massive cell death only occurred in the differentiating progenitor cells. Moreover, it have been found in a mouse leukemia model removal of ADAR1 causes massive leukemia cell death including the leukemia stem/progenitor cells within one week in all the treated animals. Delineation of the discrepant impacts of ADAR1 on normal and leukemia stem cells (LSC) might shed a light on the characterization of the leukemia stem cells and lead to a discovery of a molecular target for leukemia treatment. The goal of this project is to delineate the different impacts of ADAR1 on normal and LSC and develop a therapeutic strategy to eliminate leukemia stem cells by targeting ADAR1. Although ADAR1 is identified as an RNA editing enzyme and RNA editing has been shown to play critical roles in stem cells and other biological processes, multiple attempts to date have been unable to identify an editing target that accounts for the death of normal hematopoietic and leukemia cells of ADAR1 knockouts. It is challenging to determine RNA-editing is required for ADAR1's effects on leukemia and LSCs in the absence of a known causal edited transcript, particularly because editing-independent functions fo ADAR1 have recently been described. It is hypothesized here that the RNA editing activity of ADAR1 does not account for its function in leukemia cells. This proposal is to seek a definitive answer whether the editing activity of ADAR1 is necessary for the proliferation and differentiation of LSCs. Therefore this project will first generate a Knock-In (KI) mouse model in which an inactive ADAR1 for RNA editing is expressed from mutated endogenous ADAR1 gene. Then the impact of inactive ADAR1 on the hematopoietic and LSCs will be analyzed in the ADAR1 KI animals. HSC and LSC as well as the mature cells will be observed and compared to wild type and ADAR1 knockout cells. The knowledge obtained from this project will help to understand the LSC and leukemia development and eventually contribute to improve the leukemia treatment. PUBLIC HEALTH RELEVANCE: This project is to characterize the leukemia stem cell and has relevance with leukemia treatment.

描述（申请人提供）：本项目旨在明确造血干细胞和白血病干细胞中RNA编辑酶腺苷脱氨酶作用于RNA 1（ADAR1）的功能。特别是，将确定这些干细胞中ADAR1的RNA编辑活性的要求。 ADAR1 是胚胎和成人造血的必需蛋白，而白血病细胞更容易受到编码 ADAR1 的基因缺失的影响。 尽管在 ADAR1 缺失的情况下，移植的造血干细胞 (HSC) 在受体中的造血再生受到抑制，但归巢和自我更新能力却完好无损。 大量细胞死亡仅发生在分化的祖细胞中。此外，在小鼠白血病模型中发现 ADAR1 的去除会导致所有接受治疗的动物一周内大量白血病细胞死亡，包括白血病干/祖细胞。 描述 ADAR1 对正常干细胞和白血病干细胞 (LSC) 的不同影响可能有助于了解白血病干细胞的特征，并导致白血病治疗分子靶点的发现。该项目的目标是描绘 ADAR1 对正常和 LSC 的不同影响，并制定一种通过靶向 ADAR1 消除白血病干细胞的治疗策略。尽管 ADAR1 被确定为一种 RNA 编辑酶，并且 RNA 编辑已被证明在干细胞和其他生物过程中发挥着关键作用，但迄今为止的多次尝试仍无法确定导致 ADAR1 敲除的正常造血细胞和白血病细胞死亡的编辑靶点。 在缺乏已知因果编辑转录本的情况下，确定 ADAR1 对白血病和 LSC 的影响是否需要 RNA 编辑具有挑战性，特别是因为最近已经描述了 ADAR1 的独立于编辑的功能。这里假设 ADAR1 的 RNA 编辑活性并不能解释其在白血病细胞中的功能。本提案旨在寻求 ADAR1 的编辑活性对于 LSC 的增殖和分化是否必要的明确答案。因此，该项目将首先生成敲入（KI）小鼠模型，其中突变的内源性 ADAR1 基因表达用于 RNA 编辑的失活 ADAR1。 然后将在 ADAR1 KI 动物中分析失活的 ADAR1 对造血和 LSC 的影响。将观察 HSC 和 LSC 以及成熟细胞，并与野生型和 ADAR1 敲除细胞进行比较。 从该项目中获得的知识将有助于了解LSC和白血病的发展，并最终有助于改善白血病的治疗。 公共健康相关性：该项目旨在表征白血病干细胞并与白血病治疗相关。